docs: def delete(self, *args, **kwargs):
          """
          Delete the image, along with any generated thumbnails.
          """
          source_cache = self.get_source_cache()
          # First, delete any related thumbnails.
          self.delete_thumbnails(source_cache)
          # Next, delete the source image.
          super(ThumbnailerFieldFile, self).delete(*args, **kwargs)
          # Finally, delete the source cache entry.
          if source_cache and source_cache.pk is not None:
              source_cache.delete()